COSMO-SkyMed: the satellites continue to observe Abruzzo
The images acquired by the system for the Department of Civil Protection
03 Dec 2009
After the earthquake of 6 April, COSMO-SkyMed has continued to acquire images of Abruzzo for the Department of Civil Protection, for the purpose of surveying the earth movements in detail.
The Department’s objectives were particularly demanding due to the large size of the area concerned and the number of images that had to be acquired before they could have reliable measurements using interferometric techniques. Managing to reach the objectives in only a few months is a success story that was made possible by the unique operational capacity of COSMO.
The first results of this monitoring exercise have now been made available by the MORFEO pilot project, one of the earth observation projects undertaken in collaboration with the Department of Civil Protection. MORFEO is an acronym which in Italian stands for "landslide monitoring and risk using earth observation data". It is a coordinated research and development initiative to create a prototypal system for supporting the Department of Civil Protection in evaluating and mitigating landslide risk. In order to monitor the deformations of the Earth’s surface it predominantly uses DinSAR technology, which offers a geographic and spatially distributed vision of the deformations to complement in situ measurements and GPS. Various interferometric services are available in MORFEO, including maps of the areas to be monitored and low and high resolution maps of deformation, using SAR data in C, L and, of course, X bands.
MORFEO is processing the COSMO Abruzzo data. Two scientific groups are involved in this interferometry work: IREA-CNR and the Physics Department of the Polytechnic of Bari, together with the GAP spin-off. The scientific director of the project, coordinated by Carlo Gavazzi Space, is Fausto Guzzetti, director of the IRPI-CNR, whose task it is to produce geological interpretations of the phenomena that the satellites reveal.
The results are truly significant and have already been presented at the FRINGE workshop at ESRIN this week.
The COSMO-SkyMed images
Post-seismic velocity
COSMO has continued to acquire data regularly after the shock of 6 April. This is the ground deformation velocity map obtained by the satellites. The low resolution, processed by CNR-IREA, allows us to assess the entire deformation pattern. The area of the fault is highlighted.
Co-seismic movements
The interferogram, obtained using a DEM with a resolution of 20 metres, combines two images taken by COSMO just before (4 April) and soon after (12 April) the earthquake, and shows the effects analysed soon after the event.
Each fault is indicative of a 1.5 cm drop in ground level in the satellite’s line of sight, inclined by about 36° with respect to the vertical.
Post-seismic movements
The high resolution, processed by the Physics Department and GAP, allows detailed mapping and also allows us to see the movement of single points close to the Paganica fault (the position of which is purely indicative in this image).
In order to obtain these results 26 SAR images acquired by the COSMO-SkyMED constellation from 12 April to 20 September 2009 in stripmap image acquisition mode were processed.
Analyses are still being made, also using ground data, to calibrate the satellite measurements.
L'Aquila
This is the detailed velocity map of L’Aquila (the castle can be clearly seen).